1. Field of the Invention
The present invention pertains to a pressure plate assembly for a friction clutch, comprising a housing arrangement; a pressure plate held in the housing arrangement with freedom to move in the direction in which a rotational axis extends; a stored-energy element; a wear-compensating device acting in the path of force transmission between the stored-energy element and the pressure plate and/or the housing arrangement, which device has at least one adjusting element which can move in an adjusting direction to compensate for wear; and a clearance-producing arrangement, comprising at least one gripping element, which is attached to the assembly upon which the stored-energy element acts via the wear-compensating device. The minimum of one gripping element has a blocking section, by means of which it can make blocking contact with a blocking element when wear occurs, the clearance-producing arrangement also comprising an arresting element associated with the minimum of one gripping element. The arresting element can be displaced in the direction of the arresting motion upon the deflection, produced by the blocking system, of the minimum of one gripping element with respect to the assembly in question in order to arrest the gripping element in the deflected position associated with the amount of wear which has occurred.
2. Description of the Related Art
A pressure plate assembly with a design of this type is known from U.S. Pat. No. 6,123,180. Pressure plates of this type are usually manufactured by suppliers, who do not necessarily also produce the flywheels or clutch disks to be assembled with these pressure plates to arrive at a complete friction clutch. This means that these pressure plate assemblies are frequently delivered separately and are not attached to the clutch disks and flywheels to produce the complete friction clutches until they have arrived in the automotive assembly plant or some later production stage. This means that, in the stage before the pressure plate assembly is attached to the flywheel, there is initially no backing for the pressure plate. The stored-energy element, which is acting on the pressure plate, thus pushes the pressure plate outward from the housing arrangement; that is, there is no support such as that present after the flywheel and the clutch disk, which is situated between the pressure plate and the flywheel, have been attached. The flywheel and the clutch disk thus form a stop, which limits the movement of the pressure plate. A problem which exists in this type of production phase, i.e., the phase before the pressure plate has been attached to the flywheel, is that, as a result of the force exerted by the stored-energy element, the pressure plate can be pushed so far out of the housing arrangement that the gripping element (or the blocking section of the gripping element) enters into contact interaction with a blocking element, which can be attached, for example, to the housing arrangement. As a result, the subassemblies provided in the pressure plate assembly to respond to and to compensate for wear either go into operation or are brought into a state of readiness for such operation. This, however would ultimately mean that an unwanted wear-compensating operation would occur later, when the clutch disk is pushed back into the housing arrangement as it being attached to the flywheel and the clutch disk. The first result of this is that the friction clutch would be installed in the wrong position, and the second is that the installation position of the stored-energy element would be changed, leading to a corresponding change in its force characteristic.